Beat the Heat – Summer Essential Maintenance
24/7 Customer service
USD
Add your vehicle
Address
Login
Cart
Item
$0.00
Add your vehicle to ensure fitment/Choose a yearRequired Fields
Select a different vehicle
Make/Model
VIN
Save

Lexus IS300 Thermostat

10 items

Upgrade your vehicle's thermostat with A-Premium's high-quality options. Choose reliability and durability for a smoother ride.

  • All filters
  • Sort By
  • Year
  • Price
  • Brand
  • Material
  • Color
  • Warranty
A-Premium APTHE008 Engine Coolant ThermostatA-Premium APTHE008 Engine Coolant Thermostat
A-Premium®Part # APTHE008
A-Premium APTHE008 Engine Coolant Thermostat
4.682 Reviews
$35.99
Low stock: Only 4 left
Edit ZIP code
2-year warranty
90 days free return
Fits 2016 - 2017 Lexus GS200t, 2018 - 2019 Lexus GS300, 2016 - 2017 Lexus IS200t, 2018 - 2019 Lexus IS300, 2020 - 2022 Lexus IS300, 2023 - 2024 Lexus IS300, 2015 - 2017 Lexus NX200t, 2018 - 2021 Lexus NX300, 2016 - 2017 Lexus RC200t, 2018 - 2019 Lexus RC300, 2020 - 2021 Lexus RC300, 2023 - 2024 Lexus RC300
Add Trim and Engine info to ensure a guaranteed fit
Vehicle: Lexus IS300
Item LocatedUnited States
Quantity1
MaterialMetal and Rubber
ConditionNew
item #1005V1CR
Show less
Engine Coolant Thermostat for Toyota Prius Tacoma 4Runner Yaris Mitsubishi 82℃
A-Premium®Part # APTHE041
Engine Coolant Thermostat for Toyota Prius Tacoma 4Runner Yaris Mitsubishi 82℃
4.682 Reviews
$26.99
Low stock: Only 5 left
Edit ZIP code
2-year warranty
90 days free return
Fits 1993 - 2005 Lexus GS300, 2001 - 2005 Lexus IS300, 1992 - 2000 Lexus SC300, 2009 - 2010 Mitsubishi Lancer, 2011 - 2015 Mitsubishi Lancer, 2008 - 2010 Mitsubishi Outlander, 2004 - 2006 Scion xA, 2004 - 2006 Scion xB, 1996 - 2000 Toyota 4Runner, 2010 - 2010 Toyota 4Runner, 2000 - 2005 Toyota Echo, 1991 - 1997 Toyota Previa, 2001 - 2009 Toyota Prius, 1993 - 1998 Toyota Supra, 1994 - 1998 Toyota T100, 1995 - 2004 Toyota Tacoma, 1995 - 2015 Toyota Tacoma, 2006 - 2018 Toyota Yaris
Add Trim and Engine info to ensure a guaranteed fit
Vehicle: Lexus IS300
Item LocatedUnited States
Quantity1
ConditionNew
item #1013DWS9
Note
【Note-1】 Start to Open Temperature: 82℃.
【Note-2】 2011-2015 Mitsubishi Lancer L4 2.0L Turbocharged, NOT fits for L4 2.0L Naturally Aspirated.
Show less
Engine Coolant Thermostat Housing Assembly for Lexus GS350 GS450h IS250 IS300
A-Premium®Part # APTHA0093
Engine Coolant Thermostat Housing Assembly for Lexus GS350 GS450h IS250 IS300
4.682 Reviews
$25.99
Low stock: Only 4 left
Edit ZIP code
2-year warranty
90 days free return
Fits 2007 - 2011 Lexus GS350, 2013 - 2015 Lexus GS350, 2007 - 2011 Lexus GS450h, 2013 - 2018 Lexus GS450h, 2006 - 2015 Lexus IS250, 2016 - 2017 Lexus IS300, 2006 - 2017 Lexus IS350, 2016 - 2017 Lexus RC300, 2015 - 2017 Lexus RC350
Add Trim and Engine info to ensure a guaranteed fit
Vehicle: Lexus IS300
Item LocatedUnited States
Quantity1
MaterialPlastic
Part interchange
902-5137, 660180, 86112, 1603131020
item #1005EY6L
Show less
Engine Coolant Thermostat for Lexus IS200t IS300 GS200t GS300 NX200t NX300 82℃
A-Premium®Part # APTHE009
Engine Coolant Thermostat for Lexus IS200t IS300 GS200t GS300 NX200t NX300 82℃
4.682 Reviews
$32.99
Low stock: Only 3 left
Edit ZIP code
2-year warranty
90 days free return
Fits 2016 - 2017 Lexus GS200t, 2018 - 2019 Lexus GS300, 2016 - 2017 Lexus IS200t, 2018 - 2019 Lexus IS300, 2020 - 2022 Lexus IS300, 2023 - 2024 Lexus IS300, 2015 - 2017 Lexus NX200t, 2018 - 2021 Lexus NX300, 2016 - 2017 Lexus RC200t, 2018 - 2019 Lexus RC300, 2020 - 2022 Lexus RC300, 2023 - 2024 Lexus RC300
Add Trim and Engine info to ensure a guaranteed fit
Vehicle: Lexus IS300
Item LocatedUnited States
Quantity1
ConditionNew
item #1013DVP2
Note
Start to Open Temperature: 82℃.
Show less
ÜRO Parts TY0717617 Engine Coolant Thermostat / Water Inlet Assembly
ÜRO PartsPart # TY0717617
ÜRO Parts TY0717617 Engine Coolant Thermostat / Water Inlet Assembly
52 Reviews
$33.99
Low stock: Only 1 left
Edit ZIP code
3-year warranty
90 days free return
Fits 2006-2006 Lexus GS300, 2006-2015 Lexus IS250, 2006-2018 Lexus IS350, 2007-2011 Lexus GS350, 2007-2011 Lexus GS450h, 2013-2015 Lexus GS350, 2013-2018 Lexus GS450h, 2015-2018 Lexus RC350, 2016-2017 Lexus IS300, 2016-2017 Lexus RC300, 2018-2018 Lexus IS300
Add Trim and Engine info to ensure a guaranteed fit
Vehicle: Lexus IS300
Item LocatedUnited States
Quantity1
ColorBlack
Part interchange
TY0717617, 16031-31020, THT-004, 1430879, 902-5137, 86112, 34711, TI31082, 
...View more
item #1000ZSD6
Show less
Vemo V20-99-1281 Engine Coolant Thermostat
VemoPart # V20-99-1281
Vemo V20-99-1281 Engine Coolant Thermostat
57 Reviews
$20.99
Edit ZIP code
3-year warranty
90 days free return
Fits 1995-2000 Lexus SC300, 1995-2005 Lexus GS300, 2001-2005 Lexus IS300, 1995-1997 Toyota Previa, 1995-1998 Toyota Supra, 1995-1998 Toyota T100, 1995-2004 Toyota Tacoma, 1995-2015 Toyota Tacoma, 1996-2000 Toyota 4Runner, 2010-2010 Toyota 4Runner, 2016-2016 Toyota 4Runner, 2016-2016 Toyota Yaris, 2016-2016 Toyota Yaris, 2017-2017 Toyota Yaris, 2017-2017 Toyota Yaris, 2017-2017 Toyota Yaris
Add Trim and Engine info to ensure a guaranteed fit
Vehicle: Lexus IS300
Item LocatedUnited States
Quantity1
Part interchange
V20-99-1281, 78222, 78222S, 5324382, 29682, 29882, TX18982D, 11537791072, 
...View more
item #1001QNY1
Note
With seal
Show less
Beck/Arnley 143-0976 Engine Coolant Thermostat Housing Assembly
Beck/ArnleyPart # 143-0976
Beck/Arnley 143-0976 Engine Coolant Thermostat Housing Assembly
51 Reviews
$63.99
Edit ZIP code
3-year warranty
90 days free return
Fits 2016-2020 Lexus GS350, 2019-2021 Lexus RC300, 2019-2021 Lexus RC350, 2019-2022 Lexus IS300, 2019-2022 Lexus IS350
Add Trim and Engine info to ensure a guaranteed fit
Vehicle: Lexus IS300
Item LocatedUnited States
Quantity1
Part interchange
143-0976
item #1000XDX9
Show less
Beck/Arnley 143-0879 Engine Coolant Thermostat Housing Assembly
Beck/ArnleyPart # 143-0879
Beck/Arnley 143-0879 Engine Coolant Thermostat Housing Assembly
51 Reviews
$59.99
Edit ZIP code
3-year warranty
90 days free return
Fits 2006-2006 Lexus GS300, 2006-2015 Lexus IS250, 2006-2018 Lexus IS350, 2007-2011 Lexus GS350, 2007-2011 Lexus GS450h, 2013-2015 Lexus GS350, 2013-2018 Lexus GS450h, 2015-2017 Lexus RC350, 2016-2017 Lexus IS300, 2016-2017 Lexus RC300, 2018-2018 Lexus IS300, 2018-2018 Lexus RC300, 2018-2018 Lexus RC350
Add Trim and Engine info to ensure a guaranteed fit
Vehicle: Lexus IS300
Item LocatedUnited States
Quantity1
Part interchange
143-0879
item #1000X7SL
Show less
Beck/Arnley 143-0971 Engine Coolant Thermostat
Beck/ArnleyPart # 143-0971
Beck/Arnley 143-0971 Engine Coolant Thermostat
51 Reviews
$36.99
Edit ZIP code
3-year warranty
90 days free return
Fits 2015-2017 Lexus NX200t, 2016-2017 Lexus GS200t, 2016-2017 Lexus IS200t, 2016-2017 Lexus RC200t, 2018-2019 Lexus GS300, 2018-2021 Lexus NX300, 2018-2021 Lexus RC300, 2018-2022 Lexus IS300
Add Trim and Engine info to ensure a guaranteed fit
Vehicle: Lexus IS300
Item LocatedUnited States
QuantityOne Set
Part interchange
143-0971
item #1000XH8W
Show less
Beck/Arnley 143-0714 Engine Coolant Thermostat
Beck/ArnleyPart # 143-0714
Beck/Arnley 143-0714 Engine Coolant Thermostat
51 Reviews
$27.99
Edit ZIP code
3-year warranty
90 days free return
Fits 1992-2000 Lexus SC300, 1993-2005 Lexus GS300, 2001-2005 Lexus IS300, 2004-2006 Scion xA, 2004-2006 Scion xB, 1993-1998 Toyota Supra, 2005-2016 Toyota Tacoma, 2010-2010 Toyota 4Runner
Add Trim and Engine info to ensure a guaranteed fit
Vehicle: Lexus IS300
Item LocatedUnited States
Quantity1
Part interchange
143-0714
item #1000XD8Z
Show less

What is an engine thermostat?

 While all engines can become too hot, if your thermostat isn't working correctly, your engine's well-being is at serious risk. The engine thermostat, often simply referred to as a thermostat, regulates the engine's operating temperature within an optimal range (typically around 195 to 220 degrees Fahrenheit).

How does a car thermostat work?

As a temperature-sensitive valve within the cooling system, a car thermostat responds to changes in coolant temperature. Understanding how it works by the following breakdown steps:

  • Closed position (cold start)

Initially closed to help the engine warm up quickly.

  • Heating up

The engine generates heat during operation.

  • Opening the thermostat

A temperature-sensitive element (usually wax) causes the thermostat to open gradually.

  • Coolant flow

When open, coolant flows from the engine to the radiator.

  • Maintaining optimal temperature

Adjusts coolant flow to maintain the ideal engine temperature.

  • Temperature regulation

Continuously adjusts to prevent overheating and ensure efficient operation.

Signs of a bad thermostat

  1. Overheating: The engine becomes excessively hot due to a stuck-closed thermostat.
  2. Low or fluctuating temperature: A thermostat stuck open results in a cooler engine, affecting fuel efficiency and heating.
  3. Temperature warning light: Illuminates to indicate engine overheating due to a faulty thermostat.
  4. Poor fuel efficiency: Stuck-open thermostat reduces fuel efficiency as the engine operates less efficiently at lower temperatures.
  5. Inadequate cabin heating: Insufficient cabin heating in cold weather with a thermostat that's stuck open.
  6. Coolant leaks: Gasket or sealing issues can lead to coolant leaks.
  7. Rapid temperature fluctuations: The gauge shows rapid swings between hot and cold.
  8. Engine running hot at idle: Higher engine temperature during idle or in traffic due to restricted coolant flow.
  9. Slow or inconsistent warm-up: Longer-than-normal warm-up times, even in moderate weather.
  10. Inconsistent heater operation: This affects the performance of the vehicle's heater, causing inconsistent or inadequate heating in cold weather.

Related Blogs

Why Does Coolant Boil After You Turn the Engine Off?

Learn why coolant boils or bubbles after you turn the engine off, how heat soak affects the cooling system, and how to diagnose leaks, trapped air, cap, thermostat, fan, water pump, or head gasket problems.

Jul 29, 2026